香德祖（成奎安 饰）是一名香港皇家警察，他的老婆（王小凤 饰）怀孕待产，夫妻二人亲密非常。这一日，他们去医院检查的路上，遭遇一伙银行劫匪。出于职责，香抛下妻子奋勇上前追击。经过一番追车和搏斗，香制服歹徒，却被匪首暗算，致使钢筋穿胸而死，尸体被埋于乱铁之中。是夜，一只黑猫跳上香的身体，刚好猛雷劈下，香竟奇迹般复苏，变成活脱脱的僵尸。他复活后力大无比，但害怕阳光，还需要定期充电。香自知时日无多，决定对妻子隐瞒这个秘密，并将银行劫匪绳之以法。另一方面，匪徒当初逃跑时劫持少女Gucci（叶蕴仪 饰）为人质，混乱中Gucci拿着装钱的箱子逃跑。愤怒的劫匪四下寻找Gucci，当他们得知香还在人间之时，一番正邪大战在所难免……

Joe, a police officer, has a happy life with his wife, who's pregnant. But one day when he gets a tip that a bank is about to be robbed, he rushes to it but killed. The hostage Gucci then holds the loot. Joe becomes a vampire when a black cat jumps on his body and is hit by lightning. Not until he is sent to the hospital when he passed out, does he notice he's dead and needs electric recharge to be alive. In order to keep his wife from being sad, he doesn't tell her the truth. Even when his best friend Fung and Gucci find it out, he asks them to keep in secret. To get back the loot, the robbers seize both Gucci and Joe's wife, forcing Joe to bring the loot to exchange them. Along with Fung, Joe goes to rescue Gucci and his wife, while his wife delivers a baby. After a severe fight against the robbers, Joe finally wins but drops down as he runs out of his electric power...

향덕조는 홍콩 경찰로서 어느날 은행 강도범을 쫓다가 죽는다. 그러나 이때 천둥번개가 치면서 다시 환상하게 된다. 이런 사실을 전혀 모르는 향덕조는 자신이 죽었다가 살아났다고 생각하면서 평상시와 똑같은 생활을 한다. 그러던 어느날 갑자기 온몸에 힘이 빠져서 병원에 갔다가 자신이 강사로 변하고 일정한 시간이 경과한 후에 전기로 충전해야만 활동할 수 있다는 사실을 알게 된다. 그후 향덕조는 자신이 얼마나 살지 못한다는걸 알고 먼저 자신을 이렇게 만든 범인들을 찾아나서지만 임신을 하는데.. 아내와 함께 살고있던 소노배와 범인들이 은행에서 턴 돈을 우연히 갖게됐던 구찌가 개입돼 그들과 함께 악당들을 물리치고 자신은 운명을 달리하는데..